Please explain vsts agent error log

Hi! During agent autoupdate I can see this error in agent log ( taken from _diag/ folder):

[2018-10-29 15:53:51Z INFO SelfUpdater] Version '2.141.1' of 'agent' package available in server.
[2018-10-29 15:53:51Z INFO SelfUpdater] Current running agent version is 2.140.2
[2018-10-29 15:53:51Z INFO SelfUpdater] An update is available.
[2018-10-29 15:53:51Z INFO Terminal] WRITE LINE: Agent update in progress, do not shutdown agent.
[2018-10-29 15:53:51Z INFO Terminal] WRITE LINE: Downloading 2.141.1 agent
[2018-10-29 15:53:51Z INFO HostContext] Well known directory 'Bin': 'C:\agent33\bin'
[2018-10-29 15:53:51Z INFO HostContext] Well known directory 'Root': 'C:\agent33'
[2018-10-29 15:53:51Z INFO HostContext] Well known directory 'Work': 'C:\agent33\_work'
[2018-10-29 15:53:51Z INFO SelfUpdater] Save latest agent into C:\agent33\_work\_update\agent.zip.
[2018-10-29 15:53:52Z INFO JobDispatcher] Shutting down JobDispatcher. Make sure all WorkerDispatcher has finished.
[2018-10-29 15:53:52Z ERR  Terminal] WRITE ERROR: An error occurred: An error occurred while sending the request.
[2018-10-29 15:53:52Z ERR  AgentProcess] System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.Http.WinHttpException: The connection with the server was terminated abnormally
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Threading.Tasks.RendezvousAwaitable`1.GetResult()
   at System.Net.Http.WinHttpHandler.<StartRequest>d__105.MoveNext()
   --- End of inner exception stack trace ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at System.Net.Http.HttpClient.<FinishSendAsyncUnbuffered>d__59.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   at System.Net.Http.HttpClient.<FinishGetStreamAsync>d__33.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.Agent.Listener.SelfUpdater.<DownloadLatestAgent>d__10.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.Agent.Listener.SelfUpdater.<SelfUpdate>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.Agent.Listener.Agent.<RunAsync>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.VisualStudio.Services.Agent.Listener.Agent.<RunAsync>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.VisualStudio.Services.Agent.Listener.Agent.<RunAsync>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.Agent.Listener.Agent.<ExecuteCommand>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Services.Agent.Listener.Program.<MainAsync>d__1.MoveNext()

Could anyone explain what does it mean? ( “The connection with the server was terminated abnormally”), I’d like to address this to our netwrok team, however I’d like to get vsts agent maintainers input first … Thanks

[TingluoHuang]

@melezhik the error from that winhttp exception is:

ERROR_WINHTTP_CONNECTION_ERROR

12030

The connection with the server has been reset or terminated, or an incompatible SSL protocol was encountered. For example, WinHTTP version 5.1 does not support SSL2 unless the client specifically enables it.

https://docs.microsoft.com/en-us/windows/desktop/winhttp/error-messages

can you hit the agent download url from the machine that having the problem from IE? https://vstsagentpackage.azureedge.net/agent/2.141.1/vsts-agent-win-x64-2.141.1.zip

make sure you configure the agent to use the same proxy server as your browser.

[TingluoHuang]

i am going to close this issue as it is not an actual agent issue and the question has be answered.